Generally, an interior of a pot is filled with soil or other natural culture soil and a foliage plant planted in the natural culture soil is displayed indoors and thereby made to have a function as an interior decoration of excellent aesthetic appearance.
However, with a foliage plant using natural culture soil, odors, insects, and vermin arise due to the natural culture soil, and there is thus hesitancy against decorating such plants indoors, especially in a kitchen or a nursery and there are also problems in terms of sanitation in a restaurant, etc.
Thus, recently, arrangements have come to be known where an interior of a pot is filled with an artificial culture soil instead of a natural culture soil and a plant is planted in hydroculture, which enables cultivation by water stored in a bottom portion of the pot filled with the artificial culture soil, to not only obviously provide the function of an interior decoration of excellent aesthetic appearance but also enable sanitary indoor decoration without generation of odors, insects, and vermin (see, for example, Patent Document 1). As the artificial culture soil in this case, particulate matter, made up of an inorganic foam prepared by baking and foaming clay at a high temperature or a functional composite in which charcoal is covered with a porous ceramic, is used, and the inorganic foam is marketed under the trade name of Hydroball, etc., while the functional composite is marketed under the trade name of Neocoal, etc. Colored sand hydroculture kits, etc., of excellent interior design characteristics using hard, porous colored sand, prepared by coloring an ion exchange mineral, used as a root rot preventing agent, with a plant-based dye, in a transparent, glass pot are also being sold. In planting a plant in hydroculture, an existing pot that is appropriate for a size of the plant and is not provided with a supply and drainage hole in the bottom portion is used.
Also, the water stored in the bottom portion of the pot refers to an amount of water that becomes completely gone in approximately one week to two weeks due to water absorption by the plant, and storage of water of no less amount leads to root rot, inhibits plant growth, and causes generation of offensive odors as well as generation of insects and vermin.